Due to pollution and resource attrition, conventional fossil fuel energy sources such as coal, oil, and natural gas must soon be supplanted by renewable power sources such as solar energy. However, solar energy has not always been directly available on Earth due to atmospheric conditions. Even during clear weather, the back-scattering by the atmosphere attenuates solar power from 1400 W/m2 above the atmosphere to 1000 W/m2, at best, on Earth. Because of scattering of light in the atmosphere, the diffuse component of the 1000 W/m2 on Earth is not available for specular reflection from a concentrator to a conversion receiver. So depending on atmospheric conditions, air density fluctuations and composition, only a peak power density of about 850 W/m2 may be available for conversion in a concentrator system on Earth. However the full 1400 W/m2 is available in outer space to the micro-optics solar concentrator of the instant invention.
Even 1000 W/m2 is not always available for direct conversion on Earth, depending on time and weather. Capturing the sun's energy with a Solar Power Satellite above the atmosphere can avoid both the problems of variable weather, and of sunlight scattering in all directions from the atmosphere. A full 1400 W/m2 would be available for both direct conversion and for a concentrator system. This is one way that solar energy would be available in both good and bad weather.
The instant invention differs substantially from all previous Solar Power Satellite systems in the use of a micro-optics solar concentrator. In particular it differs from assemblages such as those of Glaser U.S. Pat. No. 3,781,647; Brown U.S. Pat. No. 3,989,994; Jung and Whalen U.S. Pat. Nos. 4,234,856 and 4,264,876; Preukschat U.S. Pat. No. 4,384,692; Fitch and Spencer U.S. Pat. No. 4,408,206; Copeland and Martin U.S. Pat. No. 4,415,759; and Simburger U.S. Pat. No. 6,127,621. None of these patents utilize a micro-optics solar concentrator. Nor do any of these patents teach or have the capability of directly reflecting and focussing sunlight to a receiver based on the ground. The U.S. Space Program successfully uses solar energy for power on board spacecraft. The instant invention enables the transmission of solar energy from orbiting satellites and even the moon to the Earth.